1. Field of the Invention
The present invention relates to a recording apparatus which intends to prevent environmental pollution, particularly to a biodegradable waste-ink absorbent of the environment protection type which will not cause environmental pollution, and is effective in absorbing a waste aqueous dye-containing ink in ink-jet recording apparatus such as printers, copying machines, and plotters for recording letters and images.
The present invention also relates to an ink-jet recording apparatus employing the above waste-ink absorbent.
The present invention further relates to an ink which will not cause environmental pollution and is useful for writing tools such as felt-tip pens, ball-point pens, and line-markers; printers for recording letters and images, copying machines, facsimile machines, plotters, and particularly ink-jet recording apparatus.
The present invention further relates to an apparatus employing the above ink.
2. Related Background Art
Hitherto, in ink-jet recording and related technical fields employing an aqueous dye-containing ink, improvement of weatherability of the ink such as lightfastness, water resistance, and ozone resistance have been studied to prevent natural deterioration of inks. Therefore, various efforts have been made to improve weatherability of the dye itself for the ink, namely the coloring matter of the ink.
For example, the number of solubilizing groups (e.g., --OH, --SO.sub.3, --COOH, etc.) in a dye molecule is decreased to raise water fastness of the dye. Such dyes are stable in a relatively high pH range because of their lower water-solubility, but tend to deposit at a pH of environmental water (pH=5.8 to 8.6). Accordingly, the dye, if discharged to the environment, is liable to deposit and accumulate in the soil, or bottoms of rivers, lakes or seas and color the ecosystem therein.
On the other hand, with increasing volumes of color image recording in recent years, high color-developing inks are coming to be consumed in a larger quantity. The consumption of water-based color inks is increasing year by year particularly in ink-jet recording and in general writing. Especially, high color-developing dyes, which give high quality recorded images, are expected to be used to a greater extent. Ideally, the aforementioned aqueous ink charged in the recording apparatus is to be used only for recording. Practically, however, not all of ink is consumed entirely by the recording, but the ink is partly recovered by a built-in mechanism called a recovery system to secure the reliability of the recording apparatus.
This recovery system serves at the start of recording to suck out a part of ink from the recording head and replace it with fresh ink to facilitate the start of recording after a long term of standing of the recording head. The ink sucked out by this step is sent through a waste ink transfer path and stored as a waste ink in a container having an ink absorbent. The absorbent which have absorbed the waste ink to its full capacity is discarded or burnt, by itself or together with the container. With increased use of the ink-jet recording system, the amount of the discarded waste-ink absorbent and the discarded container thereof is expected to further increase.
Few of the color-recorded materials prepared with the aforementioned color ink are preserved for a long term, but most of them typically are used only for temporary purposes. In other words, most of the recorded matters are discarded into the environment. The water-based color ink which has been discharged into the environment rarely deposits in the soil or on the bottom of bodies of water. The ink discharged onto the soil will cause coloring and contamination of underground water. The ink discharged into waters also will cause coloring and contamination which decreases light transmittance of the waters and destroys the fishery ecosystem by causing water-bloom growth.